JP2005515443A - Method and apparatus for determining the location of a mobile unit that tracks other mobile units - Google Patents

Abstract

The mobile location reporting communication system is composed of a network of a plurality of communication sources and a plurality of communication targets managed by one or more control stations. In this system, one communication source can request the location of the mobile communication target from the network. The communication target communicates the location to the network and that information is provided to the communication source. In the present invention, a mobile communication source requires the location of a mobile communication target that is within a defined geographic boundary. The network only provides the communication source with a plurality of remote communication targets that are within a defined boundary. Also, in the present invention, a hidden or confidential mobile portable target near the mobile portable source may be tracking the source. The source can invoke a method of revealing a mobile target that has moved with the source a predetermined distance while keeping the distance with the source close.

Description

[0001]
Background of the Invention
The present invention relates to a telecommunications service and system, and more particularly to a service and system that conveys the location of a mobile unit. The wireless industry is currently preparing to provide a wide range of location-based services to the general public. Such services include providing a subscriber with a wide range of location-based services using the location of the subscriber's portable remote unit. In order for such a service to be successful, the remote unit must be able to obtain its location information and relay it to other communication targets of the network requesting that information.
[0002]
In related prior art, such as US Pat. No. 5,689,245 by Noreen et al., The location of the remote unit was used to execute instructions specific to the location sent to the remote unit.
[0003]
In Bird US Pat. No. 5,418,537, a missing vehicle is located using a GPS receiver mounted on the vehicle. A radio paging request was broadcast by the vehicle location center when the vehicle went missing. As soon as the broadcast message is received, the vehicle analyzes the location and informs the service center of the location.
[0004]
US Pat. No. 5,539,395 to Buss proposes a remote unit that selects and displays a message that matches the location of the remote unit. The network provides the unit with a message having a location signal. A message is displayed if the location signal captured by the unit is within the current location of the unit. Otherwise, the location signal is stored in memory for display at the appropriate location.
[0005]
Chapman, US Pat. No. 5,504,491, describes a global status and location reporting system. The remote unit obtains a location on the earth and provides status and location update information to the network upon request. Such status information includes remote unit emergency situations or related situations required by the network.
[0006]
US Pat. No. 5,918,159 to Fomukong et al. Discloses a location reporting satellite paging system with the ability to arbitrarily block location reporting. In this invention, the remote mobile unit obtains its location information and provides the information over the network to other network units that request the information. Such location information is provided based on authentication information provided by the remote unit and updated daily.
[0007]
In all of the above disclosed inventions, the location of the remote unit is utilized by the system. Location service deployment can be quite beneficial to the general public if performed securely. In today's market, such mobile units are usually small, compact and lightweight. These devices can be easily hidden and their locations can be revealed without knowing or authenticating that the mobile user has disclosed their location. Most wireless users will not want to know their location on the network or the general public. And the idea that an individual's location is revealed by a secret unit hidden inside an object such as a car or luggage is not acceptable to the general public. The risk of misuse is clearly present and must be handled appropriately by radio vendors. U.S. Pat. No. 5,918,159, which proposes a location reporting authentication feature, prevents the hidden units reporting location from providing a personal location to be tracked, assuming misuse is taking place That is almost impossible for the network. Thus, there is a need for a location reporting device within a particular geographic area to reveal its location on demand. In situations where a user is being tracked, the network can determine which unit is tracking the user by examining the location of multiple remote units within a predetermined radius of the user or tracked unit. Techniques necessary to provide the above results are described in the present invention.
[0008]
When a mobile user is stuck and urgently seeking help, there may be another party with the mobile not far from the user's location. Mobile users may not be aware that there are other mobile parties in their geographic location. By making a wireless call for the location of a portable remote unit (PRU) in the area where it was stuck, the subscriber in need would be able to seek immediate help at that location. If the prescribed boundary specified by the mobile user exceeds a predetermined limit, the network can also divide the geographic area, as described below. A wireless call can be sent to a specific area to obtain the location of the portable remote unit in that geographic area. Within the geographic region closest to the user, the location of the mobile unit reporting any location is revealed to the user.
[0009]
There are many other uses that allow service providers to benefit from such services. Wireless subscribers can choose to participate in the program or be charged a fee for the user of the system each time another PRU location is provided to the user at the required geographical boundary You can also. Also, users who have portable remote units can be charged each time they activate the tracking mode with their PRU. To increase the program's registered subscribers, subscribers can also benefit from providing locations to those in need. Subscribers who do not want to disclose their location at any time can block such information on the network. In a situation where one PRU user is tracked by another user, both units have moved a distance over that predetermined period, along with a tracking unit that stays close to the communication source for a predetermined period of time. Only later will the network reveal only the location of the tracking unit. Such distance and elapsed time may be set as a standard by the industry to clearly define tracking.
[0010]
From the above, it is clear that there is a need for a system that allows a remote unit to request the location of other remote units within a particular geographic region. The configuration of such a system will be described below.
[0011]
Object of the invention
It is an object of the present invention to provide a mobile telecommunications system and method and technique thereof that can facilitate providing reliable location information associated with one or more mobile communication targets that track other mobile communication targets. It is in.
[0012]
Another object of the present invention is to provide a mobile telecommunications system that allows one communication source located within one geographic location to poll the locations of multiple communication targets located in other geographic regions. There is.
[0013]
Still another object of the present invention is to provide a technique for reporting the locations of a plurality of communication units within a predetermined boundary.
[0014]
Still another object of the present invention is to provide a suitable technique that facilitates disclosure of location information of communication units existing in a geographical area larger than usual.
[0015]
Yet another object of the present invention is to provide a remote unit that can provide location information and geographical boundary information when a search can be initiated to see if there is one or more communication targets reporting location. .
[0016]
Summary of the Invention
The foregoing and other objectives are achieved by a telecommunications system that can provide location information related to a plurality of other communication targets that lie within a predetermined geographic boundary.
[0017]
In the system, one communication source can query the locations of multiple communication targets at a given geographical boundary. The communication source can also activate a mode for determining whether another communication unit is tracking itself. Multiple communication sources and multiple communication targets of the system should be able to obtain their location using any relevant location determination technique. Based on system and subscriber requirements, this information is reliably communicated throughout the network. When a communication source requests location information for multiple communication targets within a particular geographic region, the communication source obtains its location and the geographical boundaries of the requested multiple communication targets are within the radius that it matches. Can be determined whether or not. Although the network is designed to handle all queries, the communication source can directly poll the location information of multiple communication targets within a given geographic boundary. This is possible when there is a communication target within the radius of the communication source query. This prevents unnecessary overloading of the shared network resources (network source). For more complex and more distant queries, the communication source simply provides location information and geographical boundary information, where multiple communication targets are queried for location disclosure. The network uses that resource to determine where and how to initiate a search for multiple associated communication targets. Once the search for possible communication targets within a given geographic boundary is complete, the network is closest to the communication source and one or more communication targets within the geographic area specified by the communication source Provide information related to the communication source.
[0018]
Brief Description of Drawings
FIG. 1 is a schematic diagram illustrating the present invention.
[0019]
FIG. 2 is a block diagram of a mobile portable remote unit used in the present system.
[0020]
FIG. 3 shows how to divide a larger geographical area than usual and identify the location of a remote unit within that area.
[0021]
FIG. 4 is a diagram used to determine whether a remote unit is within a defined geographic boundary.
[0022]
FIG. 5 is a flowchart illustrating a procedure used by a communication unit to determine if it is being tracked by another unit.
[0023]
FIG. 6 is a flowchart illustrating a procedure used by a communication unit to disclose a location on the earth when the unit is within a predetermined geographic region.
[0024]
FIG. 7 is a flowchart illustrating how to search for locations of a plurality of mobile communication units within a predetermined geographical boundary that is wider than normal.
[0025]
Detailed Description of the Preferred Embodiment
An overview of the system according to the present invention is shown in FIG. The system is composed of a plurality of portable remote units (PRU) 501-510 scattered over a single network or a wide geographical area. Mobile users 701 to 709 have portable remote units 501 to 509, respectively. As shown in FIG. 1, the geographic areas 201-204 are standard geographic areas that currently have one or more portable mobile users 701-709. Mobile user 701 is in geographic area 201 and mobile users 502-506 are in geographic area 202.
[0026]
Many other mobile portable users exist in the system and are interspersed as shown in FIG. The geographic locations 201-204 may be defined simply by their latitude, longitude, and radius information, or simply by a plurality of points that define their geographic boundaries as shown in FIG. Terrestrial Network Center (TNC) 801 in FIG. 1 is used to control the movement of the mobile system. The TNC communicates with ground based transmitters (GBTs) 401-404 and earth based satellite transmitters 301-302 and relays information related to mobile systems across the network. Other functions of the terrestrial network center include determining which transmitter to use to complete the call and how to prevent the call from being received when the portable remote unit leaves the jurisdiction. There is. Depending on system requirements, multiple ground control centers or network centers can be used. Ground Based Transmitting Station (GBT) 401-404 in FIG. 1 are used to relay mobile information to and from the portable mobile unit of the network. Interfaces with fixed telephone lines such as home telephones or other communication units such as personal computers can be achieved through a public switched telephone network (PTSN). The system relays information to a remote area using satellites 101-102 and also provides a reference signal. A plurality of communication units based on the ground can utilize the reference signal when establishing their geographical location. Communication between the satellite and the terrestrial network is accomplished through earth based satellite transmitters 301-302. An outline of the internal circuit of the portable remote unit or PRU 501 to 510 of FIG. 1 is shown in FIG. The portable remote unit includes an antenna 20 and a transceiver circuit 21. The transceiver circuit transmits and receives portable remote unit information via the antenna 20. Upon receipt, this information is processed, the confidential part is extracted and sent to the control unit 22 for further processing. The transceiver also receives portable remote unit information from the control unit 22, processes it, and forwards it to the network via the antenna 20 as required. The control unit 20 controls the operation of the PRU. Information relating to the PRU can be stored in the allocated memory means 26. Examples of the memory means include a random access memory, a read only memory, and an additional memory for storing PRU data. The input panel 25 is used to insert user instructions, and the display 23 is used to provide PRU information to the user. The audio means 24 is used for voice message notification. The PRU assists the network in determining its location on the earth, or uses any location determination technique to analyze the location and provide it to the network. When a PRU is taken from one location to another, it can obtain information about that latest location and provide it to the network.
[0027]
As described in one of the objects of the present invention, as shown in FIG. 1, the portable remote unit 501 used by the subscriber 701 in the moving vehicle 601 is hidden in the vehicle 601. May be tracked by a closed unit, ie, a confidential unit 510. A subscriber in another geographic area that wants to keep track of the vicinity of the user 701, for example, a subscriber 704 in the area 202, hides the unit 510 in the vehicle 601 and tracks the subscriber 701. It might have been. Most portable remote units are small and compact so that subscribers 701 can easily hide such behavior without their knowledge. As the vehicle 601 moves from one location to the next, an authenticated user can receive location information from the PRU 510 whenever polling. Since the PRU 510 discloses the location to the authenticated party, the party can obtain the location of the subscriber 710 without authentication. Most importantly, it is possible to determine whether the subscriber who owns the unit 501 is being tracked by another unit. In the present invention, the subscriber 701 can immediately activate the tracking function installed in the PRU 501 at any time. This can be accomplished by calling the appropriate function via the PRU input panel 25 of FIG. In the tracking mode, the tracked PRU 501 of FIG. 1 uses the location information of any tracking device—PRU 510— existing within a predetermined radius of the tracked PRU, so that both units are re-short-range. When the user is moving, the user who has the tracked PRU is simply alerted. Parameters such as elapsed time, shortest travel distance and tracking radius can be set as standard in the industry. The tracking function is invoked by the tracked PRU, or the request is simply forwarded to the nearest ground control center so that an operation can be performed for the tracked PRU. In the tracking mode, the geographic location of the tracked unit 501 of FIG. 1 is used to determine a geographic boundary where a search for the presence of the tracking unit 510 can be initiated. Over a period of time, at a predetermined time interval, a radio page is sent to the geographic location 201 where the tracked unit 501 has all location reporting units (all location reporting units) within that geographic boundary. exists to reveal their locations for units). The geographical boundaries needed to establish tracking could be set as a standard by the industry. For example, if one unit stays within a 5 meter radius of the tracked unit for a mile distance, it can be agreed that the unit is tracking the other unit. When the tracked unit 501 is moving, that unit or associated network unit will disclose the location of multiple other communication units within the tracked unit's tracking boundary, so that the location of those units may be Ask for. Only communication units that are within the geographical boundaries disclose their location. Timing information is also included in the disclosure information to help eliminate errors that may occur when the tracked unit 501 of FIG. 1 is inside a fast moving vehicle 601. This operation is performed over a predetermined period of time at a fixed time interval. At the first time interval, a list of all PRUs that responded within a predetermined geographical boundary defined for tracking is maintained. In the time interval after the next time, the PRUs that are in the list in the first tracking time interval and have not responded in the subsequent time interval are deleted as tracking unit candidates. At the end of the tracking period, if there is a unit in the tracking list and the minimum tracking distance is covered, then such a communication unit is considered tracking other units and requested Will be reported to the party. During the tracking period, a minimum traveling distance must be maintained to eliminate the risk of identifying multiple communication units that exist within a fixed geographic boundary as tracking unit candidates. Also, a maximum time limit must be set for the tracking operation so that the tracking process can be aborted if it has not moved the shortest distance during that time period. If such a time limit is not maintained, the PRU enters the tracking mode indefinitely. The steps of this process are shown in FIG.
[0028]
According to FIG. 5, once the tracking mode is invoked in the search unit, the tracking is initialized (FIG. 5 (1)). It should be noted that the search unit may be any relevant mobile communication unit that is trying to identify mobile communication unit candidates that are tracking other units. Therefore, until the tracking period ends (9, 13), the search unit repeats the operation during predetermined time intervals (2). In each tracking interval 2, the location of the tracked unit is obtained (3). Tracking unit candidates that are within a predetermined geographical boundary of the tracked unit are subjected to a wireless call to reveal their location (4). During the initial tracking interval (5), all tracking units that provided their location during that interval are saved in the list (7). In the following and subsequent tracking intervals, tracking units that respond during the first tracking interval but do not respond during the next interval are deleted as tracking unit candidates (6). If the tracking list is empty at any tracking interval (8), the tracking process is aborted (9). Next, test (10) is performed to verify that the tracking units in the list have moved a predetermined shortest distance. If it is determined that multiple tracking units have traveled the shortest distance (10), they are reported to the network as tracking units (11). If it is determined that the tracking unit has not yet moved the shortest distance (10), a check is made to establish whether the maximum tracking time has elapsed (12). If there is no time to establish tracking (12), the process is aborted (13), otherwise the process is repeated (2). A maximum time must be set for the tracking process so that the PRU does not enter tracking mode indefinitely.
[0029]
As mentioned earlier, the PRU can directly invoke this method to determine whether other units in the nearby geographic area are tracking the PRU. This helps reduce network overload, and at the end of the tracking period, a status signal is simply forwarded to the network. In an environment where the tracked PRU cannot perform this operation, an operation to track the PRU using the ground control unit is performed and any findings are reported to the PRU. Maintaining a list of all tracking units at the initial tracking interval is efficient because it can reduce storage space and processing time. Through the entire tracking process, it is also possible to maintain a list of all units that exist within the predefined geographical boundaries of the tracked unit. At the end of the process, the list can be used to determine which units reported their location over a predetermined distance traveled by the tracked units.
[0030]
In order for a unit to report its location on the earth within a specific geographic boundary, the unit must be able to obtain geographic boundary information and even determine whether the location is within a specified boundary. I must. Among the conventional techniques are a number of known techniques that can be used by a remote unit to determine its geographic location or to assist the network when determining its location. Once the PRU has obtained its location by some technique, the present invention uses the information to perform functions. Apart from determining whether a remote unit is being tracked, it is used for other purposes, such as for use when a remote unit discloses its location at a particular geographic location. For example, a subscriber who is in trouble with a particular terrestrial location may simply want to know if there are mobile users in a nearby geographic area. In addition, a subscriber may want to know if someone is at home, at the office, or at a particular geographic location. By identifying further information, such as the required location and radius information, the network provides the portable unit with the location of multiple portable remote targets that are closest to the PRU and within the geographic region identified by the PRU. be able to.
[0031]
For a simple search where the geographic area does not exceed a predetermined limit, all the units in that area can simply send a radio call to the required area in order to disclose their location. . Within a broader geographical boundary, it is not efficient to call these units wirelessly to reveal the location of multiple portable remote units, so the network can search for these areas differently. Manage with. In this case, the network can simply divide a wider area into multiple sub-areas and repeatedly query the locations of multiple PRUs. Before expanding to a more distant geographic area, the search begins with a sub-area near the origin.
[0032]
In order to disclose a location on the earth that is within a defined geographical boundary, a PRU that is in that geographical location and responds to a request must be within that boundary before providing that location to the network. You must decide whether. FIG. 3 shows the mobile unit M ₁ ~ M _N A certain geographical location is shown. This location can contain multiple cells (C ₁ ~ C _N ), Or multiple grids (G ₁ ~ G _N N is the total number of cells or grids and is also the area. Each zone can be defined by its latitude, longitude, and radius information, or multiple individual points that define the grid. Looking at FIG. 3, cell C ₁ Is defined by radius R and its latitude and longitude information, which is the mobile user's M ₁ (X ₀ , Y ₀ ) Information. Grid G ₁ Is four points P ₁ , P ₂ , P ₃ And P ₄ Defined by Subsequent cells and grids are defined in the same way as shown in FIG. FIG. 3 depicts a large geographic area. The ground station and control center are not shown but are also located in that area. This is illustrated in the schematic diagram of FIG.
[0033]
As shown in FIG. 3, mobile user M in need ₁ Needs to find where in the geographic area another party exists. For the closest available PRUs found within that geographic jurisdiction, the user can initiate a radio call from that PRU. In FIG. 3, the mobile user M ₁ Is region C ₁ Or grid G ₁ To the nearest available ground station with its location, latitude and longitude (X ₀ , Y ₀ )I will provide a. As mentioned earlier, appropriate terrestrial technology is provided at various locations in the area, corresponding to multiple PRUs in the area as shown in FIG. Once the ground station receives this signal, the mobile unit M in FIG. ₁ The station sends a radio call to all devices that are in a predetermined area surrounding and reporting the location and disclose their location. Such boundary information is represented by unit M. ₁ It can be easily identified by the latitude and longitude and the related radius information. First, for the first request, the radius information is a distance R as shown in FIG. One PRU within that region receives the signal and determines whether it is within a predetermined radius. Also, the ground station is the first cell G ₁ If the grid information of the PRU is specified, the PRU ₁ Boundary, P ₁ , P ₂ , P ₃ And P ₄ You must decide whether it exists in the. According to FIG. 3, the ground station is in cell C. ₁ Or grid G ₁ Mobile unit M when sending a wireless call to multiple PRU locations in ₁ Only may respond. M ₁ Since is the PRU that initiated the search, the ground control station makes a decision and obtains the next area radius or grid information that can be searched. Cell C ₂ Or grid G ₂ Geographic boundary information is provided for the next search. In subsequent searches, CRUs until a PRU within the geographic boundary responds or the system reaches its limit. ₁ To C _N Radius information or G ₁ To G _N Increase grid boundary information. What can be limited in making a wireless call for the location of a remote unit is the size of the geographical boundary. According to FIG. 3, the radius of each cell is the mobile unit M ₁ (X ₀ , Y ₀ ). The radii of the subsequent cells are the first cell C ₁ The radius of is a factor. A grid is usually a tightly closed quadrangular boundary that defines a cell. As described below, if multiple PRUs within an area need not disclose their location, exclusion areas can be identified as grids and cells become larger. Instead of expanding the next geographic area at the next radio call, it is possible to divide the entire geographic boundary into smaller areas of approximately the same size. Thus, a wireless call is made in each area starting from the area near the origin, which can be done until one PRU in one area discloses its location. Mobile unit M ₁ Considers that it has begun a search for the presence of a portable remote unit in its immediate area, the relevant ground control station sends three radio calls. The first call is cell C ₁ Or grid G ₁ To cover. Since there are no units available in the area, the second call is cell C ₂ Or grid G ₂ Sent to. Examining FIG. 3, the next PRU is cell C. ₃ Or grid G ₃ Exists only within. Once the call is in cell C ₃ PRU M when sent to ₂ And M ₃ Will respond. Grid G ₄ Is identified, PRU M ₂ , M ₃ , M ₄ And M ₅ Will respond. The ground control center is the next PRU M ₁ The unit closest to will be selected. In this case it is M ₂ It is. PRU M ₂ The location of PRU M ₁ Forwarded to M ₁ May choose to request the number of PRUs in the area, and the ground control station will respond again based on system requirements. A user who owns a PRU can use the system to check for the presence of other PRUs at different geographical locations. The user can select a geographic area from the map provided by the PRU. In FIG. 1, a mobile user 709 at location 204 may use this system to request the location of multiple mobile units in another geographic area such as 202 or 203. For example, it can be checked whether a PRU exists for an office, home, or any location of interest. The system simply returns the appropriate information, such as the number of PRUs responding, the location of the PRU and the relevant information requested. In such a system, subscribers can choose to participate in disclosure of their location when they begin a search. Subscribers can also choose to block or activate this feature at any time on the network. This service subscriber is charged a fee each time the system is used. FIG. 7 shows a technique that can be used to implement the above.
[0034]
According to FIG. 7, the geographical information of the area where the search for the presence / absence of a plurality of remote targets has been performed can be first obtained. This information is provided to the network by the PRU. This information is the latitude and longitude of the searched area and other related information for assisting the network in searching. The PRU can display a map when the user selects a particular geographic region. From this information, the next geographic area in which the PRU can be searched can be estimated (2). This information is latitude, longitude and radius information of the search area. In addition, a tightly closed rectangular grid surrounding the cell having the radius information can be calculated and used. Once that information is obtained, a wireless call is sent to the geographic area to allow the remote unit in that geographic area to determine its location (3). If multiple remote units are identified in the area that received the wireless call (4), the information is transferred to the network (5) and the process is aborted (7). If the remote unit is not confirmed in that area (4), a check is made to determine if there are cells or grids that are still in the cell or grid to be searched and that more distant cells or grids remain (6). . If there is no searchable area, the process is aborted. Otherwise, the process is repeated until it has searched for the presence of the portable remote unit for all geographic cells or grids. Whenever a portable remote unit receives a wireless call to disclose a location within a given geographic boundary, the PRU will attempt to obtain that location and determine if it is within that boundary. To do. As mentioned above, the PRU may use any relevant location determination technique known in the prior art to obtain its geographic location. If the boundary information specified by the network contains a well-defined set of points that define a geographic area—the latitude and longitude of the area—the PRU simply has its location within the geographic boundary. And provide its location to the network based on it. The points simply define the maximum and minimum latitude and longitude values within which one PRU should respond. Such a procedure is stored in the PRU's memory means (FIG. 2-26) and activated by the PRU's control unit (FIG. 2-22) upon request. If simply providing the origin of the area where the search is performed—latitude and longitude—and radius information, the PRU uses these values to place it within the area defined by the network as shown in FIG. Determine if exists.
[0035]
Figure 4 shows four objects, objects ₀ ,object ₁ ,object ₂ And objects ₃ Indicates. object ₀ Is a communication source and needs to know if there is a portable remote unit available in the geographical area of radius R. object ₀ Is the origin of the area, and the radius information of the area provided by the network is R. All objects within that radius must respond as soon as they receive a signal requesting a location within a particular radius. As shown in FIG. 4, there is an object in a specific area. ₃ And objects ₂ Will be present and will answer the radio call. If all mobile objects are served by the same ground station and they are within the area, they all receive a signal for location disclosure. To determine if they are in a particular area, each mobile object gets its location and is the communication source object ₀ A specific geographic origin defined by (X ₀ , Y ₀ ) To calculate the tangent information. The tangent of the angle is usually the opposite side / slope side. Looking at Figure 4, the tangent is the starting object ₀ And objects ₁ The angle is θ. object ₃ Is an object ₁ The object that is the starting point because it is on the same line as ₀ And objects ₃ The tangent between is also θ. The starting object ₀ And objects ₂ The tangent between is α. In the standard trigonometric equation, the tangent of the angle is the opposite side / hypotenuse. According to FIG. 4, in the case of the object 1, Tan θ = (y ₁ -Y ₀ ) / (X ₁ -X ₀ ),object ₃ In the case of (y ₃ -Y ₀ ) / (X ₃ -X ₀ ),object ₂ In the case of Tan α = (y ₂ -Y ₀ ) / (X ₂ -X ₀ ). Once the inclination angle or tangent of the object with respect to the starting point is calculated, the distance from the object to the starting point can be easily calculated using the sine formula Sineθ = opposite side / slope side. object ₁ And objects ₃ The opposite sides of (y ₁ -Y ₀ ), (Y ₃ -Y ₀ ). The hypotenuse is the distance from the mobile object to the starting point. That is, the object ₁ And objects ₃ For each R ₀₁ And R ₀₃ It is. object ₂ Then, the distance from the starting point is R ₀₂ = (Y ₂ -Y ₀ ) / Sineα. Starting point for each mobile object (X ₀ Y ₀ Once the distance from is calculated, it can be easily determined whether the mobile object is within a predetermined boundary, and based on that, the location of the mobile object is provided to the network. In addition, the network may choose to provide one or more exclusion zones to multiple portable mobile remote units or PRUs. PRUs in the exclusion zone do not disclose their location to the network, even if the network is within the specified geographic boundary. This exclusion zone is simply identified as a grid point, or as a direction from the origin, anywhere within the area that received the radio call. The direction from the origin includes information instructing a plurality of PRUs in the area not to disclose their locations when the plurality of PRUs are east, west, north, or south of the origin. Further considering FIG. 3 as an example, G ₄ Or C ₄ A request for the location of multiple mobile units within is received within the area, and the origin is M ₁ And the exclusion zone is identified as east, G ₄ Or C ₄ All mobile units within are requested to disclose their location within the area. When detecting exclusion zone information in the signal, M ₁ Only multiple mobile units to the west reveal location. Again, such exclusion zone information simply identifies one or more sub-regions where the PRU should not reveal its location.
[0036]
FIG. 6 shows the steps used by the remote unit to determine its location when the remote unit is within a geographical area identified by the network. First, the unit obtains geographical boundary information specified by the network (1). This information is composed of latitude / longitude information and radius information defining the starting point of the area. Next, the unit gets its location (2). This is done in conjunction with the network or using any remote unit location determination technique such as GPS. The next step is to determine if the unit is within the boundaries defined by the network (3). This technique has already been described in the present invention. A further check is made (4) to ensure that there are no remote units in the location reporting exclusion zone defined by the network. Once the remote unit has determined that the subscriber has authenticated such behavior (6), the location of the remote unit is provided to the network (7).
[0037]
Once a request to establish tracking is received, it can be required that all PRUs reveal their location. If the PRU is in a fixed location, it may not respond to any tracking establishment procedure. Tracking is possible only when the tracking unit and the tracked unit are moving. If the request from the network is simply to determine whether the PRU is in the geographic location, the response of the PRU is based only on the subscriber's requirement whether such behavior is authenticated If it is. The PRU can choose to instruct the network to relay information in multiple mobile units within a particular geographic area. That information is added to the geographical boundary information and transmitted to a specific geographical area. The target PRUs determine whether they are within a specific boundary before alerting the subscriber about the content of the message. When a subscriber who owns a PRU receives a request for the location of the PRU on the move, the PRU also provides the network with additional information such as this information, speed, etc. if it is within a given area. This helps to determine whether the party seeking help can catch up with another subscriber in the area seeking help. A party requesting the location of multiple remote units within a geographic boundary can also transfer maximum speed information. If a PRU exists in the area and determines that its speed is faster than a predetermined speed, it does not respond to the network. The PRU uses the equation, speed = distance / time to calculate its speed. T ₁ And T ₂ PRU is its location, Y ₁ And Y ₂ , And calculate the distance between these two disclosed points. The speed is (Y ₂ And Y ₁ Distance between) / (Y ₂ Time at -Y ₁ Time). This information is then provided to the network. If the PRU cannot perform any of the tasks described here, the network obtains its location information, performs the necessary functions on the network, and forwards it to the appropriate communication target when complete.

Claims (19)

A method for providing a location of a portable remote unit associated with a network comprising:
Obtaining the location of the remote unit;
Obtaining geographical boundary information including the location of the remote unit to be disclosed on the network;
Determining whether the remote unit is within the geographical boundaries obtained on the network;
A method of transferring the location of the remote unit to the network when it is determined that the remote unit is within the geographical boundary. A technique used in the method of claim 1 to determine whether a remote unit is within a defined geographic boundary, comprising:
Obtaining radius information of the geographical boundary from the network;
Obtaining geographical information indicating a starting point of the geographical boundary;
Calculating the tilt angle of the remote unit relative to the origin of the geographical boundary;
A technique for calculating a distance between the remote unit and the origin of the geographical boundary from the inclination angle. A technique used in the method of claim 1 to determine whether one remote unit is within a predetermined geographic boundary, comprising:
Obtaining geographical information indicating the geographical boundary from the network;
A technique for estimating the remote unit if the current location of the remote unit is within the geographical boundary obtained on the network. The method used in claim 1 to further limit the provision of remote unit locations to the network, comprising:
Obtain excluded area information on the network including remote units whose location should not be provided to the network;
A technique for determining that the remote unit does not exist in the excluded area before providing the remote unit location to the network. A method for providing the location of a plurality of portable remote units that are within a defined geographic boundary, comprising:
Redefine at least one geographical area at the prescribed geographical boundary;
Request the location of a remote unit in the area within the redefined geographic area, and each time a request is made within the redefined area, the portable remote unit will determine the location on the earth in the area. A method of providing to the network a location of at least one remote unit that verifies whether disclosed and based on the verification reveals a location within the redefined area. 6. The technique of claim 5, wherein the technique is used to terminate a request for location information of a plurality of remote units within the defined geographic boundary.
Establishes whether a request for remote unit location information was made in all redefined areas of the specified boundary, or whether a portable remote unit in one redefined area responded with location information Technology to check for. A communication system,
At least a first communication unit capable of providing location information to the network and at least a second unit, wherein the at least second unit is a geographical boundary defined by the at least second communication unit The location information of the at least first communication unit if the location of the first communication unit can be requested and is within the prescribed geographical boundary defined by the at least second communication unit. A system that can be obtained and provided. 8. The location information of the first communication unit can be provided when the at least first communication unit is within the geographical boundary defined by the at least second communication unit. system. A method for determining that a portable remote unit associated with a network is being tracked, comprising:
Obtaining a location of the portable remote unit or tracked unit, obtaining a location of at least a second communication unit or tracking unit present within a predetermined short distance of the tracked unit or within a predetermined radius;
A method of verifying whether the tracking unit and the tracked unit have moved a predetermined shortest distance and transferring the verification result to the network at the end of the tracking period. The verification technique used in the method according to claim 9,
Maintaining a tracking list of all tracking units within a predetermined radius or area of the tracked unit in a first tracking interval;
In subsequent tracking intervals, delete or delete all tracking units in the tracking list that do not report a location during the next tracking interval;
A verification technique that, at the end of the tracking period, verifies that there is at least one tracking unit in the tracking list and that the tracked unit has moved the shortest distance. Another verification technique used in the method of claim 9, comprising:
To maintain a list of all tracking units that are in close proximity to the tracked unit over the time period and to obtain a plurality of tracking units that have moved a predetermined minimum distance relative to the tracked unit Another verification technique that searches the tracking list at the end of the tracking period. A communication system,
A network composed of a plurality of communication units, and at least a first communication unit and at least a second communication unit capable of providing location information to the network, wherein the at least second communication unit has a predetermined shortest distance. A communication system capable of determining that a short distance is maintained from the at least first communication unit during movement. The at least first communication unit can invoke a tracking mode on the at least first communication unit to determine whether a confidential unit is tracking the at least first unit. The system described. A portable mobile remote unit linked to a network,
Means for obtaining a location of the portable mobile remote unit;
Means for obtaining geographical boundary information to reveal a location on the earth on the network;
A portable mobile remote unit comprising: means for providing the location of the portable mobile remote unit to the network when it is determined that the portable mobile remote unit is within the geographical boundary acquired on the network. 15. The portable mobile of claim 14, further comprising means for further determining whether to prohibit disclosure of the remote unit location at a particular geographical boundary before sending the mobile remote unit location to the network. remote. 16. The method of claim 15, comprising means for providing the speed to the network and means for further determining whether the speed was within a specified speed of the network before disclosing the location to the network. The described portable remote unit. A communication system,
At least a first communication unit and a second communication unit, wherein the at least first communication unit can request a location of the at least second unit, and the at least second communication unit includes the A communication system capable of providing location information of a second communication unit to at least a first communication unit. The system of claim 17, wherein the at least first communication unit can provide geographic boundary information for location disclosure by the at least second communication unit. Providing the location information to the at least first communication unit if the at least second communication unit is within the geographical boundary for location disclosure defined by the at least first communication unit; 18. The system of claim 17, wherein

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